In filling plants for bottles and similar containers there are usually several places, particularly upstream of high-speed processing machines such as inspection apparatus, filling apparatus or labelling apparatus, whereat the bottles or containers arriving at relatively low speed in a plurality of laterally adjacent rows have to be rearranged into a single row and to be considerably accelerated in the process. These locations are the most problematic ones of each filling plant with regard to noise and reliability of operation.
Known single-row rearrangement apparatus mostly comprise a pair of converging stationary guide surfaces forming a funnel for crowding the slowly moving stream of bottles together and for transferring the bottles onto the singlerow downstream conveyor which is driven at a faster speed. One of the two guide surfaces is frequently movably mounted or designed in the form of a roller fence or the like, whereby to avoid jamming and bridging of the bottles within the funnel-shaped rearrangement apparatus. Although the conveying efficiency of these known rearrangement apparatus is fairly satisfactory, they suffer from the disadvantage of an excessive noise level caused by the high backup pressure required for forcing the bottles through the funnel.
In DE-OS No. 30 04 259 there is described an apparatus of this type, in which the intermediate conveyor is inclined at an angle of about 5.degree., and a single guide surface for rearranging the bottle stream is located at the higher side of the intermediate conveyor. In this case, the bottles are transferred onto the faster running conveyor sections for successive acceleration solely by the guide surface extending obliquely with respect to the running direction of the conveyor. The inclination angle of about 5.degree. is insufficient for overcoming the friction of rest between the bottles' bottoms and the conveyor surface and, therefore, there will not be any lateral sliding movement of the bottles solely under a gravitational effect, hereinafter sometimes referred to as declivity drift. The inclination has the sole purpose to cause bottles lying on their side to roll downwardly, so that they are able to pass underneath a further guide surface located at the lower side of the intermediate conveyor and not participate in the formation of the bottle stream on the intermediate conveyor. In this known apparatus, the pressure between the bottles themselves and between the bottles and the guide surface, which is determined by the shape of the guide surface and by the speeds of the individual conveyor portions, is lower than in apparatus having two funnel-fashion converging guide surfaces.
Nevertheless, the emission of noise of this known apparatus even at medium operating speeds still lies considerably above a medically acceptable noise level.
In the older DE-OS No. 30 25 951 there is also described apparatus for transferring bottles arriving in an upright position in laterally adjacent rows into a single row of bottles, comprising a feed conveyor for the laterally adjacent rows of bottles, an intermediate conveyor departing from a position laterally adjacent the end section of the feed conveyor, and a succeeding downstream conveyor. In this case, the intermediate conveyor likewise consists of a plurality of laterally adjacent, parallel conveyor portions driven at stepwise increasing speeds towards one side of the downstream conveyor. Furthermore, the intermediate conveyor is slightly inclined in a direction towards the downstream conveyor. At the higher side of the intermediate conveyor, a guide surface extends obliquely thereacross for actively deflecting the bottles sidewise over the intermediate conveyor.
Also in this apparatus, the pressure exerted by the bottles on one another and on the guide surface, which is determined by the shape of the guide surface and by the speeds of the conveyor portions, is again lower than in apparatus having two funnel-fashion converging guide surfaces. Nevertheless, the noise emission also of this apparatus, even at medium operating speeds; is still so high as to represent a danger to health.
It is an object of the invention to lower the noise level of apparatus as defined in the introduction by the employ of basic provisions and without detracting from the operating efficiency of the apparatus.
For attaining this object, the invention proposes a method wherein by transversely tilting the end section of the feed carrier, the resulting declivity drift causes the bottles to be crowded together, with the bottles of the lowermost row being passively supported by a support railing, and wherein by arranging the intermediate conveyor at the same inclination as the feed conveyor and by orienting the support railing towards a lower portion of the intermediate conveyor, the declivity drift causes the bottles to migrate onto the intermediate conveyor, whereon they are cause to slide over the successive acceleration zones so as to arrive at the maximum speed zone in a spaced arrangement, said support railing extending over the intermediate conveyor in such a curved arrangment that the lowermost bottles are biased into engagement with the support railing by the declivity drift also in the acceleration zones, while the bottles which are still at a higher level and are therefore accelerated with some delay are caused by the declivity drift to support themselves on the lower bottles and to intrude into the spaces formed therebetween. Thus the lateral movement of the bottles or similar containers over the intermediate conveyor, i.e. over the acceleration zones, is not brought about by the employ of any positively or actively acting guide surface, but solely by making use of the declivity drift. An arrangement of this kind was hitherto considered impossible by those skilled in the art, as it requires the intermediate conveyor to be tilted to a considerable degree for ensuring sufficient slippage of the bottles on its surface. On the other hand, such tilting of the conveyor makes the toppling of the bottles practically inavoidable.
In the case of a bottle depallettizing apparatus it has as a matter of fact already been tried to push the bottle standing on a tilted pallet by means of a pusher bar extending over the full width of the pallet onto a multiple-stage conveyor arranged in front of the pallet and at the same inclination and onto an inclined table located alongside thereof, and to let the bottles drift freely across the table and the conveyor under the influence of gravity. In this arrangement (DE-GM No. 1,975,166), however, the bottles lack lateral support, so that they are inclined to topple over. The conveyor consists of four laterally adjacent parallel belts driven at stepwise varying speeds. On pushing the bottles off the pallet and onto these laterally adjacent conveyor belts, the bottles are abruptly accelerated from the stationary condition to the respective conveyor speed without finding any support in the conveying direction by adjacent bottles due to the fact that the acceleration causes the bottles to be drawn out into a widely spaced arrangement. The most unfavourable conditions are obviously those prevailing at the lowermost conveyor belt having the highest speed, which functions also as the downstream conveyor in this known arrangement. After having been pushed off the pallet onto the upper portion of the table, the bottles slide down without any support towards the uppermost conveyor belt, whereat they are abruptly accelerated from their transverse movement to a relatively high speed in the conveying direction extending at right angles to the transverse movement, causing them to topple over in most cases. In addition, the bottles are arranged on the pallet not in laterally adjacent rows, but in alternately offset rows, so that each bottle of the offset rows comes to be positioned on a line separating two adjacent conveyor belts running at different speeds. During their transverse drift movement the bottles are practically without lateral support, so that even small jolts may cause the bottles to topple over.
The invention has most surprisingly succeeded in obviating this toppling tendency. Due to the fact that the lowermost row of bottles is already supported along the end section of the feed conveyor by the railing provided thereat, while the adjacent rows of bottles find support on the respective subjacent rows of bottles, and that further the bottles of the lowermost row are supported even in the acceleration zones by the support railing receding at an acute angle thereto, while the bottles which are still at a higher level are caused by the declivity drift to crowd the bottles at lower levels, a continuous and passive support for all bottles is ensured during their sliding or drifting movement.
The method according to the invention may be practiced by the employ of an apparatus wherein the end section of the feed conveyor laterally adjacent the intermediate conveyor and the section of the downstream conveyor succeeding the intermediate conveyor are inclined in the same manner as the intermediate conveyor and at such an angle that the resulting declivity drift causes the bottles to slide downwards over the laterally adjacent conveyor portions of the intermediate conveyor, the lowermost side of the feed conveyor being provided with a support railing connected adjacent the intermediate conveyor to the guide surface, the latter being formed as a support surface supporting the bottles at the lower side of the intermediate conveyor.
In accordance with the invention, it has been found particularly advantageous that the angle of inclination of the conveyor surfaces of the intermediate conveyor, the feed conveyor, and the downstream conveyor be about 10.degree. to 12.degree. with respect to the horizontal.